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TT: Fachverband Tiefe Temperaturen

TT 44: Poster Session Correlated Electrons

TT 44.83: Poster

Thursday, March 17, 2011, 10:00–13:00, P1

(contribution withdrawn) Quantum Phases of the Planar Antiferromagnetic J₁-J₂-J₃ Heisenberg-Model — •Rachid Darradi¹, Johannes Reuther², Peter Wölfle², Wolfram Brenig¹, Marcelo Arlego³, and Johannes Richte⁴ — ¹Institut für Theoretische Physik, Technische Universität Braunschweig, 38106 Braunschweig, Germany — ²Institut für Theorie der Kondensierten Materie, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany — ³Departamento de Física, Universidad Nacional de La Plata, C.C. 67, 1900 La Plata, Argentina — ⁴Institut für Theoretische Physik, Universität Magdeburg, 39016 Magdeburg, Germany

We present results of a complementary analysis of the frustrated planar J₁-J₂-J₃ spin-1/2 quantum-antiferromagnet. Using dynamical functional renormalization group, high-order coupled cluster calculations, and series expansion based on the flow equation method, we have calculated generalized momentum resolved susceptibilities, the ground state energy, the magnetic order parameter, and the elementary excitation gap. From these we determine a quantum phase diagram which shows a large window of a quantum paramagnetic phase situated between the Neel, spiral and collinear states, which are present already in the classical J₁-J₂-J₃ antiferromagnet. Our findings are consistent with substantial plaquette correlations in the quantum paramagnetic phase. The extent of the quantum paramagnetic region is found to be in satisfying agreement between the three different approaches we have employed.